python: Fix conda environment not auto-activated in remote terminal (#50895)

Xin Zhao created 

Closes #50619

In the conda activation script building procedure, Zed currently
performs a file check for the conda executable on the client side. When
in remote development, this check always fails because the file exists
on the remote host, not the local machine. Since `pet` already handles
existence checks, removing this redundant check allows the activation to
proceed. It is also better to let any potential issues (like
permissions) show up in the terminal rather than silently skipping the
activation.

This addresses the root cause for remote development, which is different
from the approach in #50715 that focuses on shell hooks.

**The video recording**


https://github.com/user-attachments/assets/62967351-e3c5-4814-aec4-b2332940e7e3

Before you mark this PR as ready for review, make sure that you have:
- [x] Added a solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [x] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- Fixed conda environment not auto-activating in the terminal during
remote development sessions.

Change summary

crates/languages/src/python.rs | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

Detailed changes

crates/languages/src/python.rs 🔗 

@@ -1378,12 +1378,9 @@ impl ToolchainLister for PythonToolchainProvider {
 
             match toolchain.environment.kind {
                 Some(PythonEnvironmentKind::Conda) => {
-                    let Some(manager_info) = &toolchain.environment.manager else {
+                    if toolchain.environment.manager.is_none() {
                         return vec![];
                     };
-                    if smol::fs::metadata(&manager_info.executable).await.is_err() {
-                        return vec![];
-                    }
 
                     let manager = match conda_manager {
                         settings::CondaManager::Conda => "conda",